METHODS: We investigated the ocular permeation of topical tazocin after single drop application in normal rabbit eyes by estimating piperacillin and tazobactam concentrations in cornea, aqueous, and vitreous using a validated LC-MS/MS method. Furthermore, we determined the efficacy of repeated dose administration of tazocin against experimentally induced P. aeruginosa keratitis in rabbits in comparison to moxifloxacin. To determine the efficacy, clinical examination, histopathological examination, and estimation of bacterial load and inflammatory cytokines in cornea were done.
RESULTS: Significant corneal concentration of piperacillin and tazobactam was detected in normal rabbit corneas after single dose treatment with tazocin. In rabbits with Pseudomonas-induced keratitis, topical tazocin caused significant clinical and histopathological improvement. This improvement was associated with reduction in corneal bacterial load and inflammatory cytokines. Compared to moxifloxacin 0.5%, tazocin treated group showed greater clinical response which was associated with higher interleukin (IL)-1β, lower tumor necrosis factor (TNF)-α, a comparable level of IL-8, greater reduction in corneal bacterial load, and lesser inflammatory cell infiltration.
CONCLUSION: Tazocin showed good ocular penetration and was effective in treatment of Pseudomonas induced keratitis in rabbits.
Materials and Methods: A retrospective review of all patients with culture-positive mycotic keratitis in Hospital Universiti Sains Malaysia over a 3-year period, from January 2015 to December 2017.
Results: This study included 27 eyes of 27 patients treated for mycotic keratitis based on a positive fungal culture. The most common predisposing factor was ocular trauma, in 22 patients (81.5%). Eleven patients (40.7%) had a presenting visual acuity worse than 6/60, due to central ulcer involvement. Approximately half of these (6 patients) experienced visual improvement post-treatment. Fusarium spp. was the most common fungus isolated (37%), followed by non-sporulating fungi and Curvularia spp. Three patients (7.4%) had corneal microperforations, which healed after gluing and bandage contact lens application. One patient (3.7%) required tectonic penetrating keratoplasty and 1 patient (3.7%) underwent evisceration. The final visual acuity was 6/18 or better in approximately half (14 patients) of our cohort and worse than 3/60 in approximately 20% (5 patients).
Conclusion: Mycotic keratitis occurred mainly in males and secondary to ocular trauma. The most common organism isolated was Fusarium spp. Although treatment may improve vision, the visual outcome is guarded.
METHODS: The Dy-based NPs were synthesized, and they were loaded onto commercial contact lenses. The loading content of the NPs and their release kinetics was determined based on the absorbance of their colloidal solution before and after soaking the contact lenses. The cytotoxicity of the NPs was evaluated, and the IC50 values of their antiamoebic activity against Acanthamoeba sp. were determined by MTT colorimetric assay, followed by observation on the morphological changes by using light microscopy. The mechanism of action of the Dy-based NPs against Acanthamoeba sp. was evaluated by DNA laddering assays.
RESULTS: The loading efficiencies of the Dy-based NPs onto the contact lens were in the range of 30.6-36.1% with respect to their initial concentration (0.5 mg ml-1 ). The Dy NPs were released with the flux approximately 5.5-11 μg cm-2 hr-1 , and the release was completed within 10 hr. The emission of the NPs consistently showed a peak at 575 nm due to Dy3+ ion, offering the possible monitoring and tracking of the NPs. The SEM images indicated the NPs are aggregated on the surface of the contact lenses. The DNA ladder assay suggested that the cells underwent DNA fragmentation, and the cell death was due most probably to necrosis, rather than apoptosis. The cytotoxicity assay of Acanthamoeba sp. suggested that Fe3 O4 -PEG, Fe3 O4 -PEG-Dy2 O3 , Dy(NO3 )3 .6H2 O and Dy(OH)3 NPs have an antiamoebic activity with the IC50 value being 4.5, 5.0, 9.5 and 22.5 μg ml-1 , respectively.
CONCLUSIONS: Overall findings in this study suggested that the Dy-based NPs can be considered as active antiamoebic agents and possess the potential as drugs against Acanthamoeba sp. The NPs could be loaded onto the contact lenses; thus, they can be potentially utilized to treat Acanthamoeba keratitis (AK).